Apparatus for making chain



March 17, 1931.

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APPARATUS FOR MAKING CHAIN Filed June 7, 1924 4 Sheets-Sheet 4 A h /W Inventorficymorzd 77. 21655 M CV1 B-AYMOND W. DULL, OF CHICAGO, ILLINOIS, ASSIGNOR TO LINK-BELT COMPANY, OF

Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE CHICAGO, ILLINOIS, .A CORPORATION OF ILLINOIS APPARATUS FOR MAKING CI-IAIN Application filed June 7, 1924, Serial No. 718,427.

My invention relates to an apparatus for making chain from a strip of sheetmetal stock and particularly to a. machlne for the continuous making and automatic assembling of the llXlkS onto a chaln.

The general obect of my invention 1s toproduce chain of the typedescribed in which hook and pintle 9 tongues are stamped from the center of the link blank and the hook and pintle end bars are bent to produce a chain, each link of which consists of fiat side bars, a relatively cylindrical hook at one end, and a pintle at the other shaped for rotation Within the hook-of the link next adjacent. One object 1 is .to provide a mechanism for producing chain ofrthe type described, With maximum cheapness and simplicity; Another object is to provide a mechanism which shall stamp the hook and pintle tongues from the center of the blank and curlthem and the endbars into finished hooks andpintles With a minimum strain upon the metal of the blank, and a minimum weakening and distortion of the fibers ofthe metal. Another object is to provide a mechanism for producing chain of the type described in which, by scoring-and by indenting each blank, the tendency of the end bars totear out shall be reduced to a minimum. Another object is to provide a mechanism for producing chain of the described type in whichthelength of the blank as it passes through the device shall vary as little as, possible during, and be reduced as little as possible, by the successive die impacts.

Gther objects Will appear from time to time in the course of the specification and claims.

I illustrate my' invention more or less diagrammatically in the accompanying drawings, wherein Figure 1 is a plan view of the strip of material operated upon, illustrating the effectiofif the successive die impacts FigureQ is a section along the line 22 of Figure 1;

t Figure 3 is-a plan View similar to Figure 1, butshowingthe under side of the stock;

Eigurel is a skeleton side elevation of the punch and die, illustrating the passage of the stock therethrough, and its formation 4 into links Figure 5 is an inverted plan View of the punch;

Figure 6 is a top plan view of the die;

Figure 7 is a section on the line 7-4? of Figure l; and

Figure 8 is a section on the line 88 of Figure l.

Likeparts are illustrated by like characters throughout the specification and drawmgs.

A is any suitable base having mounted thereupon the die block A which may be secured thereto, for example, by the Wedge downwardly drawn by the bolts A and engaging With its inclined overhanging all [i the opposite inclined Wall A of the block. The opposite side of the block is gripped by the overhanging inclined Wall A of thelbase.

B is any suitable strip of relatively resistant material upon which rest the individual die elements. These elements are gripped and aligned in anysuitablemanner, for example by the opposed holding blocks 13 ,13 which may be connected together, for example by the bolts B The individual die elements will alater be discussed in detail.

The chain is formed by the passage, between opposed die and punch elements, of the stripot stock G, which is moved forward 1y therebetween bya step-by-step movement, by any suitable feeding means, the details of which need not be shown herein. Ateach successive forward movement the punch element is moved downwardly against the die element by any suitable press mechanism. The punch and die are aligned, for example,by the verticalguiding columns, J J in rigid relation With the die block A and upon which thepnnchblock K is slidably mounted.

The punch block K is clamped into any suitable Working backing K for exampleby the set screws K in the punch block. The opposite side K of the punch block is engaged by the opposed overhanging surface K of the backingelement K K is a base element similar to the base element B of the die block. K and K are lateral clamping elements secured together about the individual punch elements in any suitable manner. a

lrlil The passage of the metal strip C over the .die block is from right to left, as shown in Figure 4. This ribbon or strip of stock C may be initially straightened and fed by any suitable means not herein shown, and is guided into the machine, for example, by the pair of opposed rollers C C which are centrally grooved as at G and are rotatable upon and axially slidable in relation to the vertical pins C C Movement of the rollers upon the pins is limited by the washers C and nuts C The rollers are preferably, but not necessarily, laterally adjustable. blocks 13 B are slotted near their ends to permit the adjustment of the pins C which are clamped in position by the nuts C, C. r

Depending from the punch block and posi tionedadjacent the point of severing of the partly completed link from the strip stock, as later described, are depending strip-engaging elements comprising the opposed, inwardly slotted, edge-gripping yokes D, D, the edges of the strip C being positioned between the inwardly projecting pairs of flanges D D The set screws D, D provide means for centering the strip C within the guiding yokes. The yokes are suspended upon, or are at the lower ends of, the cylindrical plungers D which are spring pressed by the spiral springs D which are kept in position by the guiding cores D "screw-threaded into the top of thepunch blockelement K The down ward movement of the plungers D is limited, for example by the stops D which abut against the shoulders D of the plungers.

The die block is'cut away in shape, as at D D to receive the elements D whenthe travel of the-punch brings the strip O in contact withthe die.

It will be understood that the strip 0 is guided by, and in a sense suspended between, the opposed rollers C and the opposed guiding yokes D, and. intermediate the forming v impacts is suspended between die and punch in the position shown in Figure 4. The straight sides of the link stock are not bent until after the stock has passed through the guides D Since the separate punch and die elements 7 operate in pairs upon the strip of metal passing step by step therebetween, theywill be described in pairs, and in relation to the impresslon-they make upon the stock. Asthe stock, C is passed forwardly between the rollers C it is first operated upon by a pair of prick punches L, L, upon the die, which prick punch'the corners of the future link at the inside corners where the side bars and the pintle end bar join. The top of the blank at this point is merely held against upward movement bythe opposed plane surface L In describing the effect of the various die elements, the elementand the-impression made thereby will in general be given the same in- The dicating symbol. At the next forward step of the stock it is engaged both top and bottom by the opposed, H-shaped scoring knives L on the die and L on the punch. These knives score the metal along the separation between the future hook and pintle tongues and side bars and between the opposed inner edges of the hook and pintle tongue. The scores extend from the punch marks Z, as shownin Figure 3. Since the hook tongue is necessarilymuch longer than the pintle tongue, the cross scores Z are near the pintle endof the future link. At the next forward movement of the stock, the top of thestock is engaged along the transverse score Z by the transverse severing knife L". The knife shears the metal curves the hook tongue around the curved die surface L and bends the pintle tongue around the creasing bead L ton the die, thus creasing or scoring the inside ofv the bend of the pintle tongue between the punch marks Z, Z. i he end of the future hook tongue is by this operation given its preliminary curva: ture or'formation, which preferably conforms substantially to the arc of the future hook tongue. r t the next forward step of'the stock the separation betweenthe hook and pintle tongues is enlarged by the forming element L which further bends the end of the hook and pintle tongues, the end of the hook tongue being rolled about the rounded corner Z of the yieldingly mounted block E, the block being normally held in raised position bythe spiral spring or springs E and serving to lift the strip Cfrom the block as the punch is withdrawn. At the same time, the bottom of the stock is prick punched by the punches L upon the. yielding block E, which are positioned to indent the bottom of the stock. at the opposite end of the longitudinal scores from the punch marks Z. At the next forward movement of the stockthe severing of the hook tongue from the side barsis finally completed by the inclined punch element L the forward inclined portion of which shears the hook tongue from the side bars while the opposite end of it further bends the pintl tongue about the sharp corner L of the yieldingly mounted block E. Meanwhile the transverse scoring knife L deeply scoresthe top of the stock, outlining the separation between the adjacent future links. The-punch element L has pro ecting sligh ly from both sides the parts L L 7, winch cut the notches Z P near the pintleend of the link which tralapertureof the-link, punches outor moves the hook tongue to the position shown at M in Figure 2-. Along thebase of the punch M are the inclined punch ledges M adapted to engage the side bars of the link and bend thelink into the position shown at m in Figure 2. Rounded ends M, M of the base of the punch block M operate against the corresponding die elements M M and bend the hook and pintle bars, respectively, of the link to the form shown as m, m in Figure 2.

Associated with the punch elements L and M are the spring pressed plungers P normally downwardly compressed by the spiral springs P The lower ends of the plungers engage and exert pressure against the side bars of-the link or stock and assist in freeing the stock from the punch and preventing adherence of the stock thereto.

At the next movement of the stock the cutting edge N, formed by a downward offsetting-of that end of the punch in relation to the rest ofthe punch, shears along the transverse :score 5 and against the opposed cut ting edge N of the die and severe the partly completed link from the stock As the stock is forced down by the punch prior to this severing, the side barsofthe link are engaged by the longitudinal lugs G of the yieldingly mounted block G and are locked thereby against the punch element N which is pr vided with a central portion N penetrating within the central aperture of the link, and side bar engaging surfaces l 4 inopposition to the tops of the lugs G The. pressure of theheavy spiral spring G is sufficient to straighten out the link prior to the severing, as shown in Fi ure 4, and the link when severed is firmly gripped between the block Gr and the punch element N and is carried downwardly by the downward travel of the punch.

a The curved portions i N of the punch N engage, respectively, the bent hook and pintle end bars as the link is carried downwardly by the punch, the end of the hook tongue engages the rolling die surface N and is thereby curved into the position W, as shown in Figure 4. Prior to the complet1o11 of this rolling movement the pintle tongue contacts the die surface N and is bent into the position shown in Fi 'ure 4. The rolling movement of the hook tongue is limited by the-stop N adjacent the surface N of the punch element N 5 Meanwhile the previously completed links of the chain are passing forwardly between channel iron guides H, which are connected, for example, by the cross-pieces Hflthe ends 0; of which are perforated to slide upon the pairs of vertical guides H and are kept normally in raised position, as shown in Figure 4, for example bythe spiral springs H The cross-pieces maybe engaged, for example by anysuitable element or elements H on the punch element, out of alignment with the fixed pins H and preferably engaging the cross pieces H The heads H of said pins serve as stops to limit the upward movement of the cross-pieces H and the guides H in response to the springs H It will be realized that while I have shown an operative mechanism many changes might be made in the size, shape, number and disposition of parts, and the I wish my description and drawings to be taken as in a broad sense illustrative and diagrammatic, rather than as limiting me to the s JGClllC mechanism herein shown.

The use and operation of my invention are as follows:

l manufacture chain from a ribbon or strip of sheet metal stock which is fed forwardly, step by step, between opposed punches and dies. The interval between the forward feeding movement need be only suliicient to permit the strip to more forwardly through the press the length of one link.

In order to prevent interference between the stock and the punch or die at the time of such forward movement, I provide means for lifti o the entire strip of stock from the die and for suspending it between die and punch intermediate the forming impacts, and for giving it its forward movement when so suspended and out of contact with either punch or die.

In the if rm herein shown, I move the strip upwardly, after each impact, to a. position substantially midway between punch and die, when the punch is withdrawn to its maximum height. I accomplish this lifting movement in two main steps: The yieldingly mounted block E upwardly raised by the spiral spring or springs E as soon as the punch withdrawn from contact with the strip, and the compressioi'i of the spring E is suliicient to lift the block, and with it the strip, sufficiently to break the strip C from the dies and to prevent any tendency it might otherwise have to adhere thereto. Any tendency of the strip to cling to the punch ele ments is obviated by the plunger-s P and the spiral springs T, which are shown at two points upon the punch block, which, of course,mi i ht be increased in number, if necessary under any particular working conditions. These elements, pushing upon the side bars of the link, clear the stock from the punch. As the punch is lifted, the guides D remain in contact with the opposed die surface D until the stops D engage theledges D on the plungers, this occurring in practice about midway in the upper excursion of the punch. By this time the strip has already been freed from both punch and die elements and is lifted upwardly with the punch and suspended intermediate the punch and die, as shown in Figures 4: and 7.

The strip is fed into the space between of impacts. The distortion of the metal at punch and die through the rollers G which may be made transversely adjustable in relation to each other. However, they automatically compensate, within a certain range, for variations in the thickness of the stock, and the stock is centered by the opposed converging lower surfaces of the rollers. The stock cannot be jammed or caught in the rollers, since the rollers rotate in response to the forward movement of the stock and tend always to clear it. The rollers are vertically movable and will compensate to such slight upward movement of the stock as may take place at that point in response to the upward movement of the guides D.

In the form of punch and die herein shown, the portions of the link which are forced out of the normal vlane of the strip are all bent downwardly toward the die, and it is therefore necessary to lift the strip above the die to a distance greater than the length of the hook tongue.

In the method of forming the chain herein'described, the side bars of the links are not deformed or bent until shortly before each-link is severed from the chain stock. Therefore the stock, throughout most of its excursion between punch and die, is straightedged, and can easily and efficiently be forwardly fed through the guides I).

The strip metal stock,'of which the links are formed, is a fibrous material and is, of course, tough and hard. In making links from it, it is necessary not only to render easy'the severing of the parts WhlCll have to be severed, and to make without a dam'aging'distortion of the material, but also to limit the severing andto counteract the tendency for further and unintended tearing or severing, either during manufacture or during later use of the chain. To make the severing easy, the parts to be severed are initially scored. To prevent further unintendedtearing, the lines of score are terminatedby indentations which break up the normal fibrous structure of the material and prevent the formation of continued linesof weakness and cleavage beyond the lines of score and separation. V

The weakening of the link is further avoided by performing the major severing operations not by one impact but by a succession any one point is reduced to a minimum, and

'3 at the sharp bends or corners where the material of the stock is compressed by bending the blank is provided with creases and with indentations which serve to give space for the material compressed, for example along the inside of the pintle tongue, and at the inside corners of the separation of the pintle and hook tongues from the sine bars.

The successive steps of the operation may be summarized as follows: 7

The bottom of the stock is prick punched this. severing possible or indented at the future point of separation of pintle tongue and side bars. I illustrate a sharp-pointed punch but obviously a blunt or rounded punch might be used.

As the strip moves forward one step, both the top and bottom of the link are scored with an H-shaped score, the transverse arm of the H indicating the separation between the opposed end edges of hook and pintle tongue, the side scores of the H extending along the side bars from end to end of the future inside aperture of the link.

At the next forward step a severing knife separates the hook and pintle tongues along the scoreZ and begins the rolling or curvature of the ends of the two tongues and initiates theseparation of the two tongues from the side bars.

At the next step, a second knife orpunch element further bends the ends of the two tongues and further separates them from the side bars, the end of the hook tongue being bent in an arc'substantially concentric with the future are of the completed hook. At the same step, the opposite ends of the longitudinal scores are indented as at Z to prevent further tendency of the metal to tear or fault along the line of score;

, The next step, the separation of the hook tongue from the side bars, is completed and the entire hook is bent downwardly from the stock, the pintle tongue being also further Jent. Theline of separation between the two ble function. In the first place the bending.

throws the end of the hook tongue back and enables its curved end to clear the die when the linkis carried upwardly after the forming impact and prior to its next forward movement. The bending has the further function of moving the end ofthe link down so thatit will clear and pass beneath that portion of the punch which depends beneath the other punch elements and which operates upon the severed link blank.

The link is now ready to be severed from the stock, and after its next forward movement it is sheared off along the score Z and is carried downwardly by the punch element N toward the lower forming die, where the hook and pintle tongues are bent into final form. The hook tongue, since it depends farther from the link than the. pintle tongue, is the first to contact the die and is rolled by the semi-cylindrical die surface N into cylindrical form. VVhenthe link has been carried so far down that the pintle tongue also contacts the die, it is bent into finished form.

Since it is bent or compressed more highly than thelarger hook tongue, and since the bend or angle-ismuch more acute, the crease or groove along the inside of its bend is 6X- tremely important in preventing weakening and strain of the material and in allo ing for space for the compression of the material}.

The pintle of the precedingly' completed link is positioned within the arc of the hook ton 1e as it isbeing curled into final form, an it therefore curls about the pintle and passes through the central aperture of the preceding link. The link thus completed is drawn forwardly awayrfrom the stock, and at the next movement of the stock the succeedingi' link is fed forward for separation and" final formation.

Since there are necessarily deep cavities between the individual die elements, and since these cavities tend to become filled with chips and dust, I'have provided lateral apertures R in the sides of the die block for tho eaiy removal of such foreign material. a

claim:

1. In a machine for making chain links from a strip of sheet metal stock, comprising an opposed die and punch, each having a plurality of elements positioned therealong, for progressive action upon strip stock passing therebetween, means for guiding said strip between and out of contact with said elements intermediate the forming impacts, comprising pairs of edge engaging strip guide members, one pair mounted upon the punch and one upon the die.

2. In a machine for manufacturing chain from strip stock comprising opposed die and punch elements and means for passing said strip stock therebetween, means for guiding said strip stock forwardly between said elements, and for holding said strip stock out of contact with said elements intermediate the forming impact, comprising two pairs of strip edge engaging guides, one mounted upon the die and one upon the punch, said pairs of guides being longitudinally widely spaced.

3. In a machine for making chain links H from a strip of sheet metal stock, comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressive action upon strip stock passing therebetween, means for maintaining said strip between and out of contact with said elements intermediate the forming impacts, comprising in part elements yieldingly mounted on the punch and depending therefrom, and shaped to grasp the opposed edges of the strip, and a yieldingly mounted element upon said die adapted to lift the stock from the die upon the recession of the punch.

4. In a machine for making chain links from a strip of sheet metal stock, comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressive action upon strip stock passing therebetween, means for maintaining said strip between and out of contact with said elements intermediate the forming impacts, comprising in part elements yieldingly mounted on the punch and depending thercfrom, and shaped tograsp the opposed edges of the strip, and a yieldingly mounted element upon said die adapted to lift the stock fromthe die upon the recession of the punch, said elements depending from the punchbeing adapted to remain. in contact with the die until the punch has receded from the die a predetermined distance.

5. In a machine for manufacturing chain from strip stock comprising opposed die and punch elements and means for passing strip stock therebetwecn, guides for such stock comprising a pair opposed grooved rollers rotatable about vertical axes adjacent the point of entry of the strip between the dies and punch, and a pair of supporting elements adapted to engage and partially inclose the opposite edges oi the strip, said supporting elements being longitudinally widely spaced from said rollers, one pair being mounted on the punch and one on the die.

In machine for making chain. from strip stock, comprising an opposed die and punch, each having a plurality of elements positioned thercalong for progressive action upon the strip stock passing therebetween, means for clearing said stock from said opposed punch and die elements intermediate the formin excursions of the punch, comprising guide elements depending from the punch and adapted to engage the edges of the stock, and additional stock clearing means comprising stripping plunger-s mounted along the punch and laterally aligned with the stock engaging members thereof and adapted to engage the outer edges of the stock.

7. In a machine for making, from a continuous strip of sheet metal stock. chain links having pintles and hooks struck from the center of the link, comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressive action upon strip stock passing step by step therebetween, an H-shaped scoring knife adapted to score the blank to outline the inner edges of the side bars from end to end of the inside aperture of the link and to outline the separation between the opposed edges of hook and pintle tongues, and means for indenting the surface of the blank at the ends of the longitudinal arms of the H-shaped score.

8. In a machine for making chain from strip stock comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressive action upon the strip stock passing therebetween,

a pair of rotaryguides positioned on the die adjacent the point of entry of the stock between die and punch, said guides being vertically movable, a pair of strip edge engaging members positioned on the punch at a point longitudinally spaced from the rotary guides and adapted to lift the stock from the die after a predetermined upward movement of the punch. V

9. In a machine for making chain from strip stock comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressiveaction upon the strip stock passing therebetween, a pair of rotary guides positionedon the die adjacent the point of entry or" the stock between die nd punch, said guides being vertically movable, a pair of strip edge engaging members positioned on the punchat a point longitudinaly spaced from the rotary guides and adapted to lift the stock from the die after a predetermined upward movement of the punch, said members being vertically movable in relation to the punch, and yielding means, operative upon the recession of the punch from the die, to thrust them down= wardly a predetermined distance from the face of the punch.

10. In a machine for making chain from strip stock comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressive action upon the strip stock passing therebetween, a pair of rotary guidespositioned on the die adjacent the point of entry of the stock between die and punch, said guides being vertically movable, a pair of strip edge engaging members positioned on the punch at a point longitudinally spaced from the rotary guides and adapted to lift the stock from the die after a predetermined upward movement of the punch, said members being vertically movable in relation to the punch, and yielding means, operative upon the recession of the punch from the die, to thrust them clownwardly a predetermined distance from the face of the punch, and additional stock engaging members on the punchadapted to thrust the stock downwardly away from the punch.

11. In a machine for making chain from strip stock comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressive action upon the strip stock passin therebetween, a

" pair of strip edge engaging guides positioned on the die adjacent the point of entryof the stock between die and punch, a pair of strip edge engaging supports depending from the punch at a point longitudinally spaced from said guides, the die being recessed to receive said supporting members when the punch is in operative contact with the die.

12. In a machine for making chain from strip stock comprising an opposed die and punch, each having a plurality of elements positioned therealong for progressive action upon the strip stock passing therebetween, a pair of strip edge engaging guides positioned on the die adjacent the point of entry of the stock between die'and punch, a pair of strip edge engaging supports depending from the punch at a point longitudinally spaced from said guides, the'die being recessed opposite said supports to permit the strip supported thereby to rest upon and be fully contacted by the die during the forming impact of the punch, and means for thrusting said supports downwardly from the punch upon the recession of the punch from the die, and means for limiting their down- Ward movement at a predetermined point.

Signed at Chicago, county. of Cook and State of Illinois, this 2nd day of June, 1924.

. RAYMOND W. DULL. 

